Mining method and method of land reclamation

ABSTRACT

A mining method including land reclamation and hydropower and water resources development including removing the ore from the ore body in a predetermined pattern so that the remaining ore body defines a grid network of cellular units, the ore removal being performed progressively such that adjacent cellular units are in various stages of development simultaneously and filling the mined-out cells with overburden from adjacent ore body; constructing terrace ponds above the elevation of the top of the mined-out cells, the terrace ponds being constructed from overburden material; constructing dams between adjacent terrace ponds, the dams overlying an elevated portion of the ore body previously used as a plant pillar or access entry pillar; and selectively filling the terrace ponds and pillar ponds with mill tailing slurry to a predetermined reclaimed surface elevation so that the reclaimed surface consists predominantly of a slime fraction suited to agricultural re-use of the land.

United States Patent 1 [111 3,775,984 Livingston 1 Dec. 4, 1973 MININGMETHOD AND METHOD OF 1965, pages 3-8.

LAN 1D RECLAMATION [76] Inventor: Clit'ton W. Livingston, 624

Panorama Dr., Grand Junction, Colo. 81501 [22] Filed: Aug. 18, 1971 21Appl. No.: 172,711

Related US. Application Data [62] Division of Ser. No. 14,166, Feb. 25,1970.

References Cited UNITED STATES PATENTS 7/1914 Dorr 61/35 X 1,924,7218/1933 Leubuscher 61/] 2,874,945 2/1959 McWhorter 299/19 X FOREIGNPATENTS OR APPLICATIONS 1,385,793 12/1964 France 102/23 OTHERPUBLICATIONS Lang-Mining ltabirite Canadian Mining Journal, Nov.

HIGH TERRACE TERRACE INTERMEDIATE TERRACE FUTURE PILLAR Pouo OPEN CELLWATER STORAGE LOWE R ACCESS ROAD RAM

Primary Examiner-Jacob Shapiro Attorney-Sherman & Shalloway [57]ABSTRACT A mining method including land reclamation and hydropower andwater resources development including removing the ore from the ore bodyin a predetermined pattern so that the remaining ore body defines a gridnetwork of cellular units, the ore removal being performed progressivelysuch that adjacent cellular units are in various stages oi developmentsimulta" neously and filling the mined-out cells with overburden fromadjacent ore body; constructing terrace ponds above the elevation of thetop of the mined-out cells, the terrace ponds being constructed fromoverburden material; constructing dams between adjacent terrace ponds,the dams overlying; an elevated portion of the ore body previously usedas a plant pillar or access entry pillar; and selectively filling theterrace ponds and pillar ponds with mill tailing slurry to apredetermined reclaimed surface elevation so that the reclaimed surfaceconsists predominantly of a slime fraction suited to agricultural re-useof the land.

20 Claims, 36 Drawing Figures HIGHWALL ACTIVE MINING CELLS ":JTERRACEPOND/1 :1:

INTERMEDIATE TERRACE PATENTEDUEC 41973 SHEEI OlUF 21 E C N A B R U T 5 DSHOCK FRONT PATENTEBUEC M973 SHEET OEUF 21 PATENTEU 41975 397 750984SHEEI 03UF 21 H615 I H 1 5 APPARENT I TRUE CRATER fi/g] APPARENT 76: 8

APPARENT CRATER PATENTEDDEC 4W3 SHEEI UHF 21 PAIENTEUBEE 41975 I3,775,984

SHEET OSUF 21 Q O 8 o a O o u n H O l 1 0 3 q I0 X n a II LBS. 04,1958SNOWSURFACE S 10 LBS. C-4, ICE

10 LBS. A 60 TR ENCH SNOW C3 CHURCHILL TILL //' ATLAS 6c. KEWEENAW SILTENERGY UTILIZATION NUMBER, A

DEPTH RATIO A F/G. I00

PAH-,NTED 41% 3.775995% saw 050? 21 PAIENIED U975 SIYYEISBA SHEEI' 980i21 d SCALED CHARGE DEPTH W 0 I I u 2 "I 0 f 25$ 4 5 d 6 k I I I I I 8 Il I I 8 1 I I I I I l I I I I 7 I 1 I I 7 I I RADIAL I I CRACKS I I I 6I I I I 6 I/ SECOND RING I I I I l CRACKS I I I 3 5 5 -INCREMENT ,I I NI b A1 A0 T3,: I I I 3 i I I I I I i 4 I CRATER 1 4 "7, I I C LIMIT I aB I '2 C I I I 1 I 3 3 3 (n y I /I/ I i o I I j I I I I /I I I I gFRAGMENTATION RANGE. I DOMING RANGE I AB. I an; PR. IsII UPLIFT REGION JREGJ; l I R, T I I I I I I I AIRBLAST 8.5.0. V/W R. CR] PRECONDITIONINGl I I I 4 I I I I r PS. 4 I l I ,3 W I 3 I V I 9 2 8 IV x I I h w I N II I 0 .LI I7 I I v 0 I I O I CRATERING SCALED BURDEN d I 0 I 4 o% I 4 II I 0 I 2 3 4 5 6 LEGEND:

AB. REG. Airbiost Region 850. Bond SIreng'Ih Destruction SR. SecondaryRegion V/W R. V/W Region P. R. Primary Region CR. Course Region SH.R.Shear Region AU B Auiogenous Blasting RS. Puriicle Size CB. ConventionalBlosiing FIG. l5

PATENTEB M975 SJYSBBfi SHEET UQUF 21 4 m V m T m 0.8 I i u.: 5.0 lb. O iE 0.s- I Lateral extent of bond 2 strength destruction 5 I (gas bubbleradius) 8 0.4 2' l I I i I 0.2 N 1 I l I I O 1 I I O 2 O 4 O 6 O 8 I ODEPTH RATIO A PAI-ENIED DEC 4 75 ORIENT PARALLEL t0 MAJOR JOINT'SYSTEMEND LINE A (PRIMACORD LOOP BURDEN CONTROL LINE 8 j 4I3 EN SHEET 10 0F 21DIRECTION OF ADVANCE FACE DO NOT REDUCE MINIMUM SLIDING RESISTANCE PRIMACORD LOOP LINE OF SYMMETRY D REPLACE LINE D WITH LINE C, ADD LINESFOR COMPOSITE BLASTS B AND A ON OPENING SHOT SHORT PERIOD BACK LINE EPRIMAcoRD LOOP DELAY N0.

CODE V4 V2 V3 8-1 5-2 B3 54 8'5 5'5 57 5-9 SYM Q Q C) G9 6' 0 g Q Q WDIA. IN. 9.875 9.875 9.975 9.875 9.875 9.875 9.875 9.975 9.575 5.0255.625 SUB. FT 5.91 6.17 5.27 5.17 5.79 5.47 4.97 4.97 5.18 4.50 3.70

DEPTH ft. 40.91 40.17 40.27 40.17 39.78 39.74 33.97 39.97 39.18 33.5037.70

PATENTED 41975 3 7?5 98% SHEEI 12 [1F 21 PATENTED 41573 3.775884 FIG.20b H6 200 I PATENTEDJQ mm sum mar 21 IHIIIIHIIHH Ill Him]! III CODE 5CODE 4 CODE 3 CODE 2 CODE PATENTEDBEB 419B 3.775.984 sum mar 21PATENTEBUED M973 sum 18% 21 KN 6Q

1. In the method of land reclamation including removing overburden froman extended area of ore, removing the ore from the ore body in apredetermined pattern so that the remaining ore body defines a gridnetwork of cellular units, said ore removal being performedprogressively such that adjacent cellular units are in various stages ofdevelopment simultaneously and filling the mined-out cells withoverburden from adjacent ore body; the improvement comprising: a.constructing terrace ponds above the elevation of the top of themined-out cells, said terrace ponds being constructed from overburdenmaterial; b. constructing dams between adjacent terrace ponds said damsoverlying an elevated portion of the ore body previously used as a plantpillar or access entry pillar; and c. selectively filling the terraceponds and pillar ponds with mill tailing slurry to a predeterminedreclaimed surface elevation so that the reclaimed surface consistspredominantly of a slime fraction suited to agricultural re-use of theland.
 2. The method of claim 1, wherein the over-burden material used toconstruct the terrace and pillar ponds is blasted to a predeterminedrequired size by product control blasting.
 3. The method as defined inclaim 1, further including the step of mining the pillars separating thecellular units of the ore body by cut-and-fill mining.
 4. The method asdefined in claim 3, wherein the fill material for the cut-and-fillmining steps is mill tailing slurry from an ore processing plant.
 5. Themethod as defined in claim 1, wherein the predetermined reclaimedsurface is effectively established by the height of the dykes formingthe terrace and pillar ponds and the height of the terrace and pillarponds are pre-planned to accommodate the swell factor of the materialbeing mined, said swell factor being determined by a measurement of thevolume of the material to be disposed of for a given area after themining process is complete, as compared to the volume of the materialfor the area in its original state.
 6. A method of mining, landreclamation and hydropower and water resources development wherein amining layout is established including a cellular mining grid having aneven number of rows of mining cells, the rows being divided equally by aprocessing plant pillar, the processing plant pillar being a mass of theore to be mined and centrally positioned within the cellular mininggrid, the cells being separated by barrier pillars perpendicular to theplant pillar and access entry pillars parallel to the plant pillarsseparating the rows of cells on either side of the plant pillars, thebarrier pillars and access entry pillars being of the same ore bodymaterial and having essentially the same shape and height, the saidcells being mined in a step arrangement such that various adjacent cellsare in different stages of mining completion, mining commencing at aface barrier pillar and proceeding parallel to the plant pillar towardsan ultimate mining limit, large diameter bore holes in the form ofentries being driven from the face barrier pillar into the entry andplant pillars and therethrough, cross-entries being driven from theentries perpendicular to the plant and access entry pillars through thecellular units, the level of the entries and cross-entries beingdesigned to perform trajectory control blasting in the overburden andproduct control blasting in the predefined cellular units, the entriesand cross-entries providing communication between adjacent cellularunits after the mining has proceeded to the point that the ore isremoved from the predefined cells, a processing plant for the ore minedfrom the predefined cells being positioned at the top of the ore bodyheight on the processing plant pillar and adjacent the face barrierpillar, whereby the material removed from the cells may be passedupwardly to the processing plant and the refined ore recovered and theby-products, including tailings, being passed further upwardly todisposal areas, the mined-out cells being filled with overburden fromthe ore body adjacent the previously mined cells, and terrace pondsformed above the cells by dykes to provide chambers for disposal of thetailings, the area defined by adjacent plant pillars and bound by theface barrier pillar and the mining limit defining a hydropower and waterresources development unit, termed a hydropower unit, a number of cellmining units being constructed during the course of the mining withcertain of the cellular units having been completely exhausted of theore material by cut-and-fill operations to define larger pillar recoveryunits separated by boundary pillars and the various cell recovery unitsestablishing water control chambers, providing for underground waterstorage, the improvements comprising constructing a lower pool lake bedhaving a water level below the face barrier pillar, access slots on theface barrier pillar for access to the plant pillars and access pillarsand ramps leading from the lower pool elevation to the access slots toprovide passage for motor vehicles to pillar mining entries andcross-entries, drainage tunnels, and water quality control tunnels. 7.The method as defined in claim 6, further including leaving at least onemining cell adjacent the face barrier pillar open and free of anyfilling overburden or other material for use as an open cell waterstorage area, and further constructing tunnels and raises through theface barrier pillar communicating the lower pool with the upper portionof the open cell water storage area.
 8. The method as defined in claim7, further including constructing a power generation system adjacent thelower pool water level for generating power due to the passage of waterfrom the open cell water storage tank to the lower water level.
 9. Themethod as defined in claim 8, further including means for sUpplyingwater to the processing plant constructed on the processing plantpillar.
 10. The method as defined in claim 8, further includingreclaiming water from the ore processing plant tailings by downwardpercolation of the water into broken overburden-filled mining cells,thence through filter beds placed in the bottom of the mining cells andfinally draining the water into the lower pool.
 11. The method asdefined in claim 10, further including constructing an overflowstructure and mine spillway tunnels to transfer upper pool water fromone hydropower unit to another.
 12. The method of claim 2 wherein theproduct control blasting is conducted by: i. conducting test craterblasts at various depths to determine the breakage limits of thematerial in response to the blasts; ii. preparing a chart by plottingthe slant distance to each of the types of fractures in the blastingfailure process and to the doming limit from test crater blasts; iii.establishing a grid over the crater formed by each test blast andmeasuring the particle size of the broken material touched by the grid;iv. preparing a chart by plotting the variation of the predominantparticle size with various charge depths at scaled depth ratios Delta ;v. determining in the range Delta d to Delta o from the chart of (iv)the value in the controlling burden direction at which the desiredpredominant particle size can be achieved, Delta d is the Delta value atwhich doming begins and Delta o is the value of do/N for the givencharge weight, do being the depth of placement of a charge of the givenweight which produces upon explosion of the charge maximum pressure risewithin the material, and N being the depth of placement of a charge ofthe given weight which first begins to produce upon explosion of thecharge fractures on the surface of the material in which the charge isplaced; or in the range Delta o to Delta equals 0 the value at which thedesired particle size can be achieved where predominant particle sizefrom autogenous blasting ranges from near zero to that measured at Delta0 of the crater tests; vi. decreasing the crater chart value (v) bysubtracting for bench geometry a Delta increment adjustment ranginglinearly from a maximum at Delta bo - Delta o for a controlling burdenof magnitude Delta o to zero for a controlling burden Delta a or less orfor a controlling burden Delta ss or greater, Delta increment beingDelta bo minus Delta o, Delta bo being the value of dbo/N for the givencharge weight, dbo being the perpendicular distance from the verticalfree face to the center of gravity of explosive charge which producesupon explosion of said charge maximum pressure rise within the material,a is the Delta value at which the volume of the apparent crater ismaximum, and Delta ss being the Delta value at which cratering begins;vii. placing the charge at a distance from the controlling burden towardthe face of the bench corresponding to the adjusted Delta value; viii.placing the charge at a distance from the non-controlling free face atthe crater test determined value; and i. detonating the charge.
 13. Amining method including: a removing overburden from the ore body bytrajectory control blasting; b. establishing a cellular grid structureincluding planned ore body cells separated by barrier pillarsperpendicular to entry pillars; c. driving entries in the ore bodyperpendicular to the free face in said entry pillars; d. drivingcross-entries from said entries through said planned ore body cellsperpnedicular to said entries and at the same ore body level; e.constructing over cells filled with overburden and mill tailing, rampsand terraces forming an embankment to re-establish the terrain of themined region; f. placing explosive charges in said cross-entries wIthinthe area defined by the planned ore body cells for product controlblasting; and g. detonating said explosive charges.
 14. The method ofclaim 13, wherein the trajectory control blasting is conducted bycontrolling the trajectory of material formed as bench geometrysurrounding a blast charge in response to explosion of the charge by: i.placing a charge of weight W at a vertical depth Delta v, wherein Deltav dv/N wherein dv is the vertical depth, N being the depth of placementof a charge of given weight which first begins to produce upon explosionof the charge fractures on the surface of the material in which thecharge is placed; ii. positioning said charge of weight W along arearward extension of a line perpendicular to the bench free face at aburden Delta b wherein Delta b db/N wherein db is the burden distanceand Delta b Delta v + Delta diff wherein Delta diff is a predeterminedpositive value, the trajectory being substantially in a verticaldirection when Delta v is less than Delta b and substantially in thehorizontal face direction when Delta b is less than v; and iii.detonating the charge.
 15. The method of claim 13, wherein the materialfor constructing the embankment is produced by product control blasting.16. A mining method including: a. clearing overburden from an extendedarea of underlying ore; b. excavating in a stepped fashion a grid ofcellular units in the exposed ore body, said units separated by barrierpillars; c. forming ramps in the pillars as mining progresses downwardlyfor access to the ore; and d. providing means for removing water fromstreams adjacent the area being mined during periods of high stream flowto an upper pool formed as a reuslt of the mining operation andreturning the water to the stream during low flow periods.
 17. Themining method claim 16, further including removing water containedwithin the overburden and ore body and storing the removed water indrainage collection cells and void storage cells which are constitutedas previously mined cells filled with broken overburden.
 18. The miningmethod of claim 17, further including constructing terrace ponds andpillar ponds above the previously filled mining cells for collectingsurface run-off water and passing the surface run-off water downwardlyinto the previously mined cells filled with broken overburden.
 19. Themining method of claim 18, further including controlling the flow ofwater from the drainage collection cells by valves positioned within theentries and cross-entries communiating between the mining cells tothereby direct the water through filter beds and water quality anddrainage tunnels for use in irrigation and the milling process andcollection of portions of the water in a lower pool for return asdesired to augment low stream flow.
 20. A mining method including: a.clearing overburden from an extended area of underlying ore; b.excavating in a stepped fashion a grid of cellular units in the exposedore body, said units separated by barrier pillars; c. forming ramps inthe pillars as mining progresses downwardly for access to the ore; d.drilling drain holes through the barrier pillars to provide watercontrol tunnels communicating between said cells; and e. recoveringwater used in the ore processing plant by pumping a slurry of tailingsto terrace and pillar ponds constructed above previously mined cells andfiltering water from the slurry into void storage cells.